The ship known as the American Republic sails on, but its crew made up of irresponsible and vicious children cast from “Lord of the Flies.” Prisoners of their own emotions, they increasingly seem impervious to the notion that their gyrations might topple their own vessel.

To be sure, exhibit one of infantilism in politics starts at the White House. At a time when President Trump could be laying out a case for his bold economic and foreign policies, he chooses all too often to focus on personalities, tweeting often inane, degrading and inappropriate venom at his critics.

For some Republicans, Trump sadly has become a stylistic icon. Scott Wagner, a GOP candidate running for governor in Pennsylvania, for example, claimed he would drive “stomp all over” his opponents face with his “Golf spikes”. Such intemperate candidates cost the Republicans dearly during the tea party era and could so again.

Romper room resistance

Bad behavior at the top of the GOP should present a great opportunity for the Democratic Party rule. But instead its leaders seem to be experiencing a kind of emotional breakdown, expressing themselves in hysterical, and even inquisitorial, behaviors that could erode their electoral prospects.

Whatever one thinks of the Kavanaugh hearings, it was not great advertising for turning the reins of power to them. From the beginning they made clear that they not only wanted to defeat Kavanaugh but hopefully to persecute him, largely for uncorroborated misbehavior over three decades old.

As protesters swarmed the Senate hearing room, and activists stalk GOP officials, even out dining with their families, few Democrats seem even remotely interested in controlling their unruly shock troops. No prominent Democrat has managed to stage an equivalent of Bill Clinton’s Sister Soulja moment, when he denounced openly racist rhetoric from a popular rapper.

Where’s the establishment?

In the past, excesses on both sides would be restrained by a functioning establishment in each party. Americans historically dislike hierarchy, but an engaged class of patricians, party bosses and their associated intellectual wing people often managed to restrain their partisans from going too far from basic political norms.

Two institutions now overwhelmingly controlled by progressives — the media and the academy — are increasingly seen as highly partisan. Yet as each of these have become identified almost exclusively with the agenda of the Democrats, they have lost popular influence, with approval ratings at historic lows. For its part the last remnants of the rogue pro-Trump media, notably Fox and the right-wing talkocracy, also seem to be talking largely to their own true believers.

Needed: A patriotic common ground

In the past American politics have been as heated, but outside of the Civil War, republican norms have held. Many northern Democrats rallied to support the war effort under Lincoln. President Franklin Roosevelt’s “court-packing” efforts were denounced by many in his own party. Rightist opponents of American intervention in the Second World War embraced our war effort once Pearl Harbor was attacked.

Four decades later, Richard Nixon’s fate was sealed not by progressive Democrats but by moderates like North Carolina’s Sen. Sam Ervin and the conservative icon Barry Goldwater. Most Americans, after 9-11, rallied behind President Bush while, in the early days of the financial crisis, most Americans supported President Obama’s efforts to rescue the economy.

In all those trying times, we had adult supervision in both parties loyal to the country’s traditions and the Constitution. Now we have a president clearly ignorant of democratic norms faced by an opposition that has contempt for them. On the left, increasingly, many want to subvert the Constitution, eliminating the Electoral College, reconstituting the Senate and packing the Supreme Court. A writer for the leftist Slate denounced the court as “historically repressive and presently expendable institution.” Others openly suggest that we would have been better off losing the Revolution to the British.

It is tragic that progressivism is losing its once proud rootedness in American tradition. The often overtly post-patriotic rhetoric would have shocked great progressives like the Roosevelts, Harry Truman or John Kennedy, hard-edged nationalists all. The basic concept that we are a nation of communities, individuals and families is now being supplanted with the politically correct idea of being little more than various group identities. This is not a game winner. Four out of five Americans, including minorities, reject the political-correctness approach, according to one recent national survey. Barely 8 percent of the population identify as progressive activist.

Conservatives face a similar danger. Only a decided minority of Americans call themselves a conservative, so their future lies in moving to more middle of the road voters. Republicans and conservatives should not, as they increasingly do, back off criticism of Trump when he makes vile statements about opponents, immigrants or women — all critical to the party’s future. Sometimes the infantile 70-something needs to be taken to the rhetorical woodshed, and damn the tweets.

Until our political elites restore some sort of political or moral center, the nation’s political culture will continue to deteriorate. A hugely powerful nation that is armed to the teeth and ruled by a bratocracy is a threat not just to itself but the world.

Joel Kotkin is the R.C. Hobbs Presidential Fellow in Urban Futures at Chapman University in Orange and executive director of the Houston-based Center for Opportunity Urbanism (www.opportunityurbanism.org).